from the Forum department...Modbus mapping registor reading at register plus 1
why the modbus mapping register is visible at register address +/- 1 address.
By Jay on 24 April, 2014 - 1:34 am -
Hi, the numbering is introduced in the official Modbus Application Protocol Specification (page...
Guys who live in cubes write the code. Hence, it depends on whether the guy who wrote the code...
from the Automation and EMS department...Unity Pro communications
Need help for communication of NOE with M340.
By Brian Cervi on 23 April, 2014 - 4:16 pm -
This is compatibility error due to upgrade of firmware in NOE. Likely Unity V5 does not support the...
from the Urgent department...Time and Date in Honeywell control builder
How could use time and date in control module?
By Robert Perez on 23 April, 2014 - 6:56 am -
Hi Mostafa, I saw your pictures, please go to the CM tree at your left and under the root node...
> Could you upload a picture showing your control builder? ...
By Robert Perez on 19 April, 2014 - 8:56 am -
> but unfortunately i couldn't find variables CEE1.HOUR...... > i have many control module...
thank you so much sir but unfortunately i couldn't find variables CEE1.HOUR...... i have many...
By Robert Perez on 9 April, 2014 - 9:05 am -
Hi Mostafa, you could get the hour, minute and second variables from the CEE under the...
from the ENG department...Triconex system
What happens when Triconex system CPU fails?
from the Forum department...Yokogawa error message
Yokogawa error message
By Steve Martin on 23 April, 2014 - 12:10 am -
You've basically created a tag without it being registered in the taglist. This can be done if you...
from the Automation List department...Android tablet for HMI?
Using an Android tablet as an all in one PLC.
By Peter Fredriksson on 22 April, 2014 - 4:32 pm -
Hello, I hope you all will not see my post as a advertisement. We are a small family company...
By Ramses on 10 April, 2014 - 2:18 pm -
Hello, I found a very good free apps for android and IOs devices (Iphone, Ipad) that is a SCADA...
from the Modbus department...S7 PLC as a MODBUS slave
would like to make S7 PLC as a MODBUS slave and a PC Master MODBUS
By Steve Myres on 22 April, 2014 - 1:27 pm -
Forgot to mention in my previous post. The reason I distinguished between tech and business aspects...
By Steve Myres on 22 April, 2014 - 12:14 pm -
Have never done it using the Siemens Ethernet port, but I have done that on a 315-2DP using a...
from the gad trubine control system department...moog servo valve operation
How does a MOOG servo valve operate?
Jyshen, You are most welcome....
By Jyshen on 22 April, 2014 - 6:00 am -
Dear CSA, Thanks for your superb informative response. Your passion and sincerity to share your...
from the Forum department...Driving a Stepper Motor
I am seeking advice on the best methods to effectively control a stepper motor.
from the Instrumentation department...ML1400 PLC communicate PIC 16f874 over modbus protocol
ML1400 PLC communicate with PIC 16f874 over modbus protocol and write data to LCD connected to microcontroller
from the Automation department...DCS Yokogawa Communication Issue
Yokogawa DCS communication with Modbus slave device using ethernet redundant connection with ALE111.
By Elbert van der Bijl on 17 April, 2014 - 5:15 am -
this behavior is by design and it will not occur when the Modbus slave is correctly responding to...
from the Automation and EMS department...Modbus Data transmission time
How to calculate time to receive data from slave to master in daisy chain connection of slaves, if my slaves are 20 and single master.
By Patrick Lansdorf on 16 April, 2014 - 1:55 am -
Hi, I have made a simple Excel sheet, where one can calculate the line time. You will need to...
By Steve Myres on 15 April, 2014 - 12:55 pm -
Slick idea on the prefetch! ...
By Lynn August Linse on 15 April, 2014 - 9:31 am -
>> What's a rule-of-thumb value for >> RTU-TCP latency in a Digi Modbus bridge...
By Bhadresh Sarvaiya on 15 April, 2014 - 1:29 am -
> Mr. Linse, > What's a rule-of-thumb value for RTU-TCP latency in a Digi Modbus bridge...
Mr. Linse, What's a rule-of-thumb value for RTU-TCP latency in a Digi Modbus bridge product? ...
By Lynn August Linse on 14 April, 2014 - 10:36 am -
Just be careful to accommodate the delay-back off during failure. With a single device, it might...
By Bhadresh Sarvaiya on 13 April, 2014 - 5:14 am -
Thank you for your kind reply.. but i didn't get answer as i want.. i didn't understand your...
You know - the word size, 11 bits - the number of words in the master message - silent...
from the Forum department...SCADA RTU in Substation
Why use SCADA RTU in a substation? What is the purpose of SCADA RTU?
from the Forum department...8-bit data types in Modbus registers
Are 8-bit data types obsolete for Modbus?
By Lynn August Linse on 14 April, 2014 - 10:39 am -
A bit of historical trivia... Modbus never had 8-bit data types. The original PLC were made back in...
> Since registers are always 16 bits, does it even make sense to provide data types of 8 bits...
from the Engineering department...Siemens marshaling wire
Brand name of Siemens' 0.5mm thick marshaling wire
from the Annoying Exceptions department...Negative Acknowledge and Bad Karma
How do you feel about security exceptions not being, you know, informative?
By JulieInAustin on 13 April, 2014 - 2:24 pm -
> What product are you working on, and are there any other security enhancements you are making?...
from the Automation List department...Interfacing VFD with PLC
How to interface variable frequency drives with PLCs?
By N.A. on 12 April, 2014 - 5:02 am -
If You Want only on/off control from PLC, then connect the drive to digital output module. and if...
from the Forum department...Connecting Honeywell UDC via Modbus TCP/IP to Modicon quantum
Connecting a Honeywell UDC temperature controller to Modicon PLC via Modbus. any ideas on this?
Latest edition of Honeywell's Modbus RTU communications manual 51-22-25-66, Rev T, dated February...
from the maintenance department...Process Switches NO NC definition
What "normally" means in process switches.
By N.A. on 11 April, 2014 - 1:51 am -
Dear Sir, Normally means then initial condition of any switch or relay without pressing or...
from the Instruments Department department...Modbus Max. Length
Measure the total Modbus Length
By Curt Wuollet on 10 April, 2014 - 9:31 pm -
No that's a star and it's a bad idea because 20 M of unterminated cable will give you reflections...
By Franco Kew on 10 April, 2014 - 5:43 am -
Dear CWW, Maybe I use the wrong wording in my post, but I am not using the star topology. I try...
By Steve Myres on 9 April, 2014 - 1:01 pm -
Hadn't thought of segmenting the network with repeaters to fix the topology - slick! Franco,...
By Lynn August Linse on 9 April, 2014 - 9:46 am -
This is an RS-485 issue, not Modbus question. Max length is more an issue of the cable quality...
from the Instrumentation department...communication between siemens PLC S7-400 to DCS Centum CS3000R3
Communication between SIEMENS S7-400 PLC Scalance card to Yokogawa DCS CENTUM CS3000R3
you need to use Siemens CS-3000 module to convert your signal to modbus TCP/IP signal and interface...
By Patrick Lansdorf on 10 April, 2014 - 2:17 am -
Hi, I am guessing that the PLC is a Profibus master... You can use a gateway, such as: ...
from the Forum department...Flow Rate Calculations S7-1200
Flow Rate Calculations S7-1200
from the Forum department...2oo3D voting
Explain if 1oo2D voting is just similar to 2oo3 voting for ESD system.
Let's start with your requirement of tripping of valve on rise of line pressure beyond high limit....
Demand the establishment of the government
in its rightful home at Disneyland.